Hello atmosphere,
Agreed.
Standing waves result in room bass modes which are perceived as bass exaggeration, attenuation or even cancellation at the specific points they occur at in the room. These room bass modes resulting from standing waves also vary by frequency and typically exist in the bass frequencies up to about 350 Hz.
As I understand how the distributed bass array concept functions, the 4 subs distributed throughout the room actually are intended to create more bass standing waves and bass modes that are fairly well distributed throughout the entire room.
Once there's a good distribution of bass room modes existing in a given room, the principles of psycho-acoustics are then utilized by the DBA concept. Humans are very poor at discerning the originating source of deep bass frequencies (below about 80-100 Hz) but very sensitive in discerning the pitch and the volume of these deep bass frequencies as well as any changes in pitch and volume. Our brains process these multiple bass room modes (bass peaks and dips at various frequencies) by summing and averaging them which results in a perceived smoothing effect to the bass.
Scientific research by Earl Geddes, Floyd O'Toole and others has proven that the more subs in a given room the more the effects of bass standing waves are reduced and the more the bass response is perceived as good(accurate, smooth and detailed). They realized there's a practical limit to the acceptable number of subs in a domestic room, however, and their data showed that some of the bass smoothing effect began with as few as 2 subs in a given room but there was a threshold reached with 4 subs in a given room which mitigated the effects of the vast majority of standing waves in the entire room, with each additional sub beyond 4 only providing smaller and marginal improvements.
This means that 4 subs will assure very good bass response at all bass frequencies throughout the entire room, including the chosen dedicated listening position. 2 subs cannot provide very good bass response throughout the entire room, only at a single dedicated listening position and this very good bass response cannot be assured at all frequencies and with all recordings.
Tim
Agreed.
Standing waves result in room bass modes which are perceived as bass exaggeration, attenuation or even cancellation at the specific points they occur at in the room. These room bass modes resulting from standing waves also vary by frequency and typically exist in the bass frequencies up to about 350 Hz.
As I understand how the distributed bass array concept functions, the 4 subs distributed throughout the room actually are intended to create more bass standing waves and bass modes that are fairly well distributed throughout the entire room.
Once there's a good distribution of bass room modes existing in a given room, the principles of psycho-acoustics are then utilized by the DBA concept. Humans are very poor at discerning the originating source of deep bass frequencies (below about 80-100 Hz) but very sensitive in discerning the pitch and the volume of these deep bass frequencies as well as any changes in pitch and volume. Our brains process these multiple bass room modes (bass peaks and dips at various frequencies) by summing and averaging them which results in a perceived smoothing effect to the bass.
Scientific research by Earl Geddes, Floyd O'Toole and others has proven that the more subs in a given room the more the effects of bass standing waves are reduced and the more the bass response is perceived as good(accurate, smooth and detailed). They realized there's a practical limit to the acceptable number of subs in a domestic room, however, and their data showed that some of the bass smoothing effect began with as few as 2 subs in a given room but there was a threshold reached with 4 subs in a given room which mitigated the effects of the vast majority of standing waves in the entire room, with each additional sub beyond 4 only providing smaller and marginal improvements.
This means that 4 subs will assure very good bass response at all bass frequencies throughout the entire room, including the chosen dedicated listening position. 2 subs cannot provide very good bass response throughout the entire room, only at a single dedicated listening position and this very good bass response cannot be assured at all frequencies and with all recordings.
Tim